Linear Carp – the rare type of carp

Carp fishing for sport is getting quite popular in North America, even though the fish itself is considered a pest and not eaten by anglers.

There are many types of carp in the world. Some are more popular than others.

The most popular are Common, Mirror, and Koi Carp, and even a few Asian guests like Silver, Bighead, and Grass Carp.

Linear Carp is one of the rarer types of carp. The Linear Carp is more popular in Eastern Europe and Russia than in North America and Western Europe.

What is a Linear Carp?

From a genetic point of view, Linear Carp is one of King Carp (common carp) species, with Common, Mirror, and Leather Carp. 

Linear Carp are not very often seen in the wild, but it is quite a popular fish in commercial fisheries that try and stock this fish for their guests because of its rarity.

If you are an avid carp angler, you might have caught one yourself, or if you are just starting, there is a slight chance you will catch one at some point.

Habitat

The Linear Carp spends most of its time in shallow waters, 3 – 12 ft deep, and likes to stick to the shade of overhanging trees or under cover of grown reeds along the shoreline.

Like most other carp species, Linear Carp is an omnivore and eats pretty much everything he doesn’t need to chase, like insects and their larvae, crustaceans, plenty of aquatic flora, and organic matter (detritus) from the bottom.

Unlike other carp species, Linear Carp cannot survive long under oxygen deficit, and it’s not a very hardy fish overall.

It is a difficult feat to breed Linear Carp. Many European aquaculturists stopped breeding this fish because of its low resistance to diseases and very low tolerance to cold.

Origin

The origin of Linear Carp is not entirely known, but many scientists in Poland and the former USSR managed to breed them in captivity from Common Carp.

The process was very similar to one of Mirror Carp’s creations. Over time, one of the genotypes mutated. In the case of Mirror Carp, it was S -> s, and in the case of a Linear Carp, it was n -> N.

Linear Carp’s survival rate is comparatively low in comparison with other carp species. 

The Leather Carp can be bred with other King Carp species or each other, but the later cross renders at least 25% of the offspring unviable, which means that more than 1/4 dies right after hatching.

What does a Linear Carp look like

The Linear Carp always has a very level row of scales along the lateral line

In addition, a dorsal row of scales begins at the head or the dorsal fin base reaching the tail.

These scales typically stretch vertically and are compressed horizontally.

Sometimes, additional, more or less complete rows of very even scales are visible above or below the “main” row. 

Continuous elegant rows of scales may cover the bodies of some Linear Carp. 

The one row of scales is often the only one on the Linear Carp, and that could be the reason why anglers wrongly name it a Mirror Carp.

Linear Carp are mostly yellowish-green or brownish-green in color. They usually weigh around 10 – 20 lbs, but some record specimens were reaching over 40 lbs.

What’s the Difference Between a Linear Carp and a Mirror Carp?

linear carp

The first difference between Linear and Mirror Carp is in the scale pattern.

The scale pattern is controlled by genotypes, with two alleles each. 

For Mirror Carp, the phenotype is “ssnn,” and it is recessive homozygous. The Linear Carp’s scale pattern, on the other hand, is heterozygous “SSNn” or “SsNn.” 

The difference in the genes between Mirror and Linear Carp makes them two different types of carp

Apart from scale patterns, there are few other differences in appearance between Linear and Mirror carp.

The fin structure is another difference. Linear Carp has partly reduced fins, with 10 – 21 soft rays, whereas Mirror Carp has 16 – 24.

Next on the list of differences is a number of gill rakers on the first arch. Mirror Carp has more rakers, 22 – 28. At the same time, Linear Carp has between 16 – 23.

On top of the pattern, there is also a different number of scales along the lateral line. Linear Carp usually has 32 – 39 scales. Mirror Carp usually has less than 32.

Linear Carp has a more elongated body than Mirror Carp, and its dorsal fin is usually shorter. 

Linear Koi Carp

Different scale cover and patterns also occur in Koi Carp, and that includes linear patterns as well. 

All variants of reduced scale cover in Koi are called doitsu

There are more than 100 types of Koi colors and scale patterns, and they all have separate names.

The linear pattern in Koi Carp is called kagamigoi.

The Linear Koi Carp have identical phenotypes as King Carp species, which is “SsNn” or “SSNn.”

Generally, Linear Koi Carp is not the desired type because of its slow growth and low survival rates. 

They are more prone to suffer from various morphological defects, such as reduced fins, barbels, and lateral line, and spinal deformities.

Can You Eat Linear Carp?

Although in Europe carp is a valued dinner fare, as mentioned before, not many anglers choose to eat carp in the U.S.

Linear Carp is edible, same as other carp types, although whether you choose to eat this rare type of carp or not is up to you.

Linear Carp, just like Common or Mirror Carp, per 100 g of fish contains 127 calories, 18 g proteins, and 5,6 g of fat. 

Considering the Linear Carp is a bottom feeder, sometimes the meat can have a little bit of a “muddy” taste, but the best option is to pan-fry it with a bit of seasoning.

How to Catch Linear Carp

As Linear Carp spends most of its time in the shallows under overhanging trees, a fly rod has a significant chance of success.

There are also multiple rigs made primarily to fish for carp. They will also work well for Linear Carp.

A very popular rig to catch a Linear Carp is the basket or bottom feeder. 

The list of bait for Linear Carp contains semolina balls, sweet corn, boilies, maggots, marshmallows, and bread dough.

Resources

Selective breeding fo carp and intensification of fish in breeding ponds, Valentin S. Kirpitchnikov, 1966

Genetic resources of common carp at the Fish Culture Research Institute, Szarvas, Hungary, J. Bakos, S. Gorda, 2001

Biology and Ecology of Carp, Constanze Pietsch, Philipp E. Hirsch, 2015

Genetics and breeding of common carp, Valentin S. Kirpitchnikov, 1999

Fish genetics. Theory and practice, Boris Gomelsky, 2011